The patch titled
Subject: thp: make MADV_HUGEPAGE check for mm->def_flags
has been added to the -mm tree. Its filename is
thp-make-madv_hugepage-check-for-mm-def_flags.patch
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------------------------------------------------------
From: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
Subject: thp: make MADV_HUGEPAGE check for mm->def_flags
This adds a check to hugepage_madvise(), to refuse MADV_HUGEPAGE if
VM_NOHUGEPAGE is set in mm->def_flags. On s390, the VM_NOHUGEPAGE flag
will be set in mm->def_flags for kvm processes, to prevent any future thp
mappings. In order to also prevent MADV_HUGEPAGE on such an mm,
hugepage_madvise() should check mm->def_flags.
Signed-off-by: Gerald Schaefer <gerald.schaefer@xxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Hillf Danton <dhillf@xxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Cc: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 4 ++++
1 file changed, 4 insertions(+)
diff -puN mm/huge_memory.c~thp-make-madv_hugepage-check-for-mm-def_flags mm/huge_memory.c
--- a/mm/huge_memory.c~thp-make-madv_hugepage-check-for-mm-def_flags
+++ a/mm/huge_memory.c
@@ -1450,6 +1450,8 @@ out:
int hugepage_madvise(struct vm_area_struct *vma,
unsigned long *vm_flags, int advice)
{
+ struct mm_struct *mm = vma->vm_mm;
+
switch (advice) {
case MADV_HUGEPAGE:
/*
@@ -1457,6 +1459,8 @@ int hugepage_madvise(struct vm_area_stru
*/
if (*vm_flags & (VM_HUGEPAGE | VM_NO_THP))
return -EINVAL;
+ if (mm->def_flags & VM_NOHUGEPAGE)
+ return -EINVAL;
*vm_flags &= ~VM_NOHUGEPAGE;
*vm_flags |= VM_HUGEPAGE;
/*
_
Patches currently in -mm which might be from gerald.schaefer@xxxxxxxxxx are
linux-next.patch
thp-remove-assumptions-on-pgtable_t-type.patch
thp-introduce-pmdp_invalidate.patch
thp-make-madv_hugepage-check-for-mm-def_flags.patch
thp-s390-thp-splitting-backend-for-s390.patch
thp-s390-thp-pagetable-pre-allocation-for-s390.patch
thp-s390-disable-thp-for-kvm-host-on-s390.patch
thp-s390-architecture-backend-for-thp-on-s390.patch
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